review 1080p video lag on my new computer

I buy a new computer,dual e5 2683v3 32g ddr4ecc and qudaro m4000
so I think that's better than my old e3 and gtx670 computer.
but no,it's still review lag ,even 1080p.I installed Quicktime,open cuda engine and update my driver to newest.
it's still so lag,even I use 1/4 resolution to review.
and when i finish my video. I use MediaEncoder to export video to h264,it's just use my 20% cpu and 17%gpu.i don't know why it's slower than my old computer.
CC 2015 not support dual cpu and m4000?or it just my setting have some trouble?

For Premiere editing, you are usually better off with a fast Core i7 processor than dual XEONs. Also, a GTX 980 display card would be a faster solution than the M4000. That said, your system should certainly be quite fast enough for smooth playback.

What are the specifics of the footage being played, and your video storage drive setup? Those would be factors I would look at.

In addition to what Jeff said about not having media assets on the system drive, and using the USB 3.0 port. You have to consider the layout of your system and data flow. It's not just keeping media files off the system drive, it's also avoiding any other drives or ports that share resources with the same buss as the system drive. Therefore, if you have more than one USB 3 ports, trying another port might make the difference.

Another thing to consider is audio conforms and cache file locations. Where are those being save to? Same as the project drive, or a temp folder on the system drive?

Think of your PC like a super highway. You want the fastest drives/largest data sets to have the fastest lane to themselves.